[0001] Various embodiments of the present technique relate generally to sampling techniques,
and more particularly to a system and method for compressively sampling a signal of
interest.
[0002] Success of digital data acquisition processes has placed enormous pressure on signal
processing hardware and software to support higher resolutions, denser sampling, a
large number of sensors and an even larger number of modalities. Conventionally, digital
data acquisition processes employ the Nyquist-Shannon sampling theorem that provides
uniform sampling of data at the Nyquist rate, that is, at twice the bandwidth. However,
most signals are sparse and contain several coefficients close to or equal to zero
when represented in a linear transform domain, such as, frequency, wavelet or time.
Therefore, sampling these sparse signals at the Nyquist rate, which is a worst-case
threshold for any band-limited data, results in oversampling of the signal. This oversampling
may further result in unnecessary computation, storage and battery requirements, thereby
severely limiting the capabilities and performance of digital devices such as cameras,
microarrays and wireless sensor networks.
[0003] Compressive sensing (CS) is an emerging field that provides a framework for efficient
sampling of sparse signals using sub-Nyquist sampling rates. By employing CS, a sparse
signal can be perfectly reconstructed, or robustly approximated, from a small set
of random projections even in the presence of noise with sub-Nyquist sampling rates.
Particularly, CS exploits
a priori signal sparsity information for estimating signals in the presence of noise and solving
signal restoration and imaging problems. Moreover, each compressively sampled measurement
may include substantially the same amount of information, thereby simplifying the
encoding and quantization processes.
[0004] Compressive sensing, therefore, has been applied in a variety of technology areas
such as inventory management, homeland security, healthcare, Magnetic Resonance Imaging
(MRI), and geo-sensing applications. Most CS systems, however, are customized for
specific application requirements with each CS component being custom built to perform
a specific set of functions. Such customization burdens the available space, power
and computational resources of devices using multiple sensors that sample multiple
signals for implementing feature-rich applications. Moreover, use of these customized
components limit scalability and adaptability of the CS systems. Additionally, such
configurations fail to allow updates to existing functions or dynamic mitigation of
detected software and hardware errors.
[0005] It may therefore be desirable to develop a generic sampling technique for compressively
sampling a plurality of signals even in the absence of prior knowledge or assumptions
about the signals and corresponding applications. Particularly, there is a need for
an adaptive system and method for dynamically configuring CS protocols based on a
specified set of parameters for implementing desired functions and achieving a desired
sampling performance.
[0006] In accordance with certain aspects of the present technique, a method for configuring
a sensor chassis is presented. The method includes remotely receiving a set of parameters
for compressively sampling an input signal. Further, a CS protocol for compressively
sampling the input signal may be dynamically determined based on the remotely received
set of parameters for achieving a desired sampling performance. Subsequently, the
input signal is compressively sampled according to the determined CS protocol.
[0007] In accordance with a further aspect of the present technique, a sensor chassis is
disclosed. The sensor chassis includes a receiver that receives an input signal and
a processing subsystem that remotely receives a set of parameters for compressively
sampling the input signal. Further, the processing subsystem may dynamically determine
a CS protocol for compressively sampling the input signal based on the remotely received
set of parameters for achieving a desired sampling performance. To that end, the sensor
chassis may include one or more programmable filters, where each programmable filter
has at least one setting whose value may be adjusted according to the determined CS
protocol. Subsequently, the sensor chassis compressively samples the input signal
according to the determined CS protocol. Various features, aspects, and advantages
of the present technique will become better understood when the following detailed
description is read with reference to the accompanying drawings in which like characters
represent like parts throughout the drawings, wherein:
FIG. 1 is a block diagram of an exemplary environment for a system that facilitates
dynamic configuration of a sensor chassis, in accordance with aspects of the present
technique;
FIG. 2 is a block diagram of a sensor chassis that dynamically determines a CS protocol
for compressively sampling an input signal, in accordance with aspects of the present
technique;
FIG. 3 is a flow chart illustrating an exemplary method for dynamically configuring
a sensor chassis, in accordance with aspects of the present technique;
FIG. 4 is a graphical representation of a plurality of input signal characteristics;
and
FIG. 5 is a flow chart illustrating another exemplary method for compressively sampling
an input signal, in accordance with aspects of the present technique.
[0008] The following description presents a technique for dynamically configuring a sensor
chassis for compressively sampling an input signal. Particularly, embodiments illustrated
hereinafter describe a sensor chassis and a method for dynamically configuring the
sensor chassis to compressively sample the input signal based on one or more received
parameters. Although the following description includes only a few embodiments, the
present technique may be implemented in many different operating environments and
systems for compressively sampling a plurality of signals of interest. By way of example,
the present technique may be used in environment monitoring, inventory management,
homeland security, healthcare, Magnetic Resonance Imaging (MRI), and wireless sensing
applications. An exemplary environment that is suitable for practising various implementations
of the present technique will be discussed in the following sections with reference
to FIG. 1.
[0009] FIG. 1 illustrates an exemplary environment 100 that facilitates dynamic configuration
of a sensor chassis 102, in accordance with aspects of the present technique. For
clarity, an exemplary implementation of the present technique will be described in
the context of monitoring the environment 100 for evaluating emergency situations.
In one embodiment, the environment 100 may include a first sensor 104 for sensing
a first input signal 106, such as a radio frequency (RF) signal, traversing a particular
region in the environment 100. The environment 100 may further include a second sensor
108 for monitoring a second signal 110. The second signal 110 may include a spatially
varying phenomenon such as temperature, light or moisture in the particular region
traversed by the first input signal 106. For purposes of discussion, however, the
present technique will be described with reference to the dynamic configuration of
the sensor chassis 102 for compressively sampling the first input signal 106. Further,
it may be appreciated that although FIG. 1 illustrates two sensors, fewer or more
sensors may be deployed to sense fewer or more signals and a corresponding set of
parameters in the environment 100 as per application or user requirements. In one
embodiment, the set of parameters may include an environmental datum associated with
the first input signal 106, a characteristic of the first input signal 106, and so
on. By way of example, the environmental datum may include at least one of an ambient
noise bandwidth, an ambient noise duty cycle, an ambient noise power spectral density,
an ambient noise average power and an ambient noise peak power. Further, the input
signal characteristic may include at least one of the input signal bandwidth, the
input signal duty cycle, the input signal power spectral density, the input signal
average power and the input signal peak power.
[0010] Additionally, the set of parameters may also include a parameter corresponding to
the sensor chassis 102 (sensor chassis parameter) and a criterion specifying the desired
sampling performance. By way of example, the sensor chassis parameter may include
a type of analog-to-digital converter (ADC) to be used, a sampling rate, a desired
number of bits per sample, or combinations thereof. Moreover, the desired sampling
performance may correspond to a maximum acceptable difference between the first input
signal 106 and a signal reconstructed according to the determined CS protocol. As
used herein, the term "maximum acceptable difference" is defined as a reconstruction
not differing from the first input signal 106 by more than a determined amount in
a voltage or a power domain.
[0011] In accordance with aspects of the present technique, the set of parameters may be
transmitted to a computing device 112 communicatively coupled to the sensors 104 and
108 over a communication network 114. The communication network 114 may include either
or both of wired networks such as LAN and cable, and wireless networks such as WLAN,
cellular networks, and/or satellite networks. Particularly, the set of parameters
may be remotely received by the computing device 112 over the communication network
114. These parameters may generally be referred to as a remotely received set of parameters.
As used herein, the term "remotely received set of parameters" refers to the set of
parameters that may be indirectly received by the computing device 112 through a receiver
116 operatively coupled to at least one of the sensors 104 and 108, a user interface
118, a digital communication link 120 or a data repository 122 coupled to the computing
device 112 over the communication network 114. In certain embodiments, however, the
term "remotely received set of parameters" refers to the set of parameters that may
be indirectly received by the sensor chassis 102 through the receiver 116 operatively
coupled to at least one of the sensors 104 and 108, the user interface 118, the digital
communication link 120 or the data repository 122 over the communication network 114.
[0012] Further, in accordance with aspects of the present technique, the computing device
112 may evaluate the remotely received set of parameters to determine one or more
characteristics corresponding to the first input signal 106 and desired application
and/or user requirements. For example, in case of a fire that originates in the particular
region, one or more obstructions may block certain paths to an exit. The computing
device 112 may evaluate the set of parameters received during a particular time interval
from the sensors 104 and 108 positioned in and around the particular region. Particularly,
the computing device 112 may evaluate a change in temperature that may be detected
by the second sensor 108 to efficiently locate the fire. Additionally, the computing
device 112 may also evaluate a change in determined positions of one or more objects
in the particular region detected by the first sensor 104 to ascertain if objects
have moved to create obstructions to the exit. The evaluation, thus, may allow security
personnel to locate and evacuate people quickly and efficiently. To that end, the
computing device 112 may include a processor 124 and a memory 126 for evaluating the
received set of parameters. By way of example, the processor 124 may include one or
more microprocessors, microcomputers, microcontrollers, dual core processors, and
so forth. The processor 124 may dynamically determine a CS protocol for compressively
sampling the first input signal 106 based on the remotely received set of parameters.
Particularly, the processor 124 may evaluate the set of parameters to determine the
CS protocol that may be used by the sensor chassis 102 to compressively sample the
first input signal 106 to achieve the desired sampling performance.
[0013] In accordance with a further aspect of the present technique, the processor 124 may
store one or more instructions corresponding to the determined CS protocol on a storage
device coupled to the computing device 112. In a presently contemplated configuration,
the processor 124 may store the one or more instructions corresponding to the determined
CS protocol on a sampling control unit 128. In such a configuration the sampling control
unit 128 may be an independent unit physically removed from the computing device 112
and/or the sensor chassis 102. In one embodiment, the independent sampling control
unit 128 may initially be communicatively coupled to the computing device 112 for
facilitating the processor 124 to program and store the one or more instructions on
the sampling control unit 128. Subsequently, the sampling control unit 128, thus programmed
by the processor 124, may be communicatively coupled to the sensor chassis 102 for
compressively sampling the first input signal 106 based on the determined CS protocol.
In accordance with aspects of the present technique, the sampling control unit 128
may include at least one of a memory device, a programmable device, and/or instructions
received through a control device operatively coupled to the sensor chassis 102. Particularly,
in one implementation, the sampling control unit 128 may include a field programmable
gate array (FPGA). The FPGA implementation may allow dynamic configuration of multiple
CS protocols, thus providing immense scalability and adaptability to the sensor chassis
102. Alternatively, the sampling control unit 128 may be implemented as an optical
disk, a tape, a compact disk, and so on. The exemplary implementation, thus, may enable
fabrication of a generic sensor chassis that may be configured 'on the fly' to dynamically
select an appropriate CS protocol for sampling any received input signal. Such a generic
sensor chassis may reduce the time and complexity involved in manufacturing and operating
the sensor chassis. Additionally, the generic sensor chassis may also facilitate sampling
of a plurality of input signals based on the structure of the input signals and ambient
conditions.
[0014] Turning to FIG. 2, a block diagram 200 of one embodiment of a sensor chassis 202
that dynamically determines a CS protocol for compressively sampling an input signal
is presented. To that end, the sensor chassis 202 may include a receiver 204 and one
or more input devices 206 such as a user interface, a keyboard, and so on to receive
the input signal such as the first input signal 106 of FIG. 1 and a corresponding
set of parameters. Particularly, in the present embodiment, the sensor chassis 202
may remotely receive the input signal 106 and the corresponding set of parameters
from at least one of the set of sensors 104 and 108 of FIG. 1, a user interface coupled
to the input device 206, the digital communication link 120 of FIG. 1 or the data
repository 122 of FIG. 1. Accordingly, the set of sensors 104 and 108, the user interface,
the digital communication link 120 and the data repository 122 may be communicatively
coupled to the sensor chassis 202. The sensor chassis 202 may further include a digitizing
system 208, a sampling control unit 210, and memory 212 coupled to a processing subsystem
214 for sampling the received input signal 106. In the embodiment illustrated in FIG.
2, the sampling control unit 210 may have one or more structural and/or functional
similarities with the sampling control unit 128 of FIG. 1. In the embodiment illustrated
in FIG. 2, however, the sampling control unit 210may be an integral part of the sensor
chassis 202 and may not be an independent unit like the sampling control unit 128.
[0015] In accordance with aspects of the present technique, the processing subsystem 214
may use one or more parameters corresponding to the sampled input signal 106 to monitor
the sampling performance of the sensor chassis 202. In case the desired sampling performance
is not achieved, the sensor chassis 202 may provide an alert through an output device
218 coupled to the sensor chassis 202. Subsequently, in certain embodiments, the processing
subsystem 214 may further customize the determined CS protocol to achieve the desired
sampling performance upon receiving the alert through the output device 218. By way
of example, the output device 218 may include visual indicators such as a display
and blinking lights, audio indicators such as speakers, and so on. Additionally, the
sensor chassis 202 may include a power source 216 for operating the sensor chassis
202. The power source 216 may include a battery, line power, solar or wind powered
cells, and so on to suit desired application and deployment needs. By way of example,
in an air sampling system, the sensor chassis 202 may use a solar powered cell as
the power source 216, whereas in a deep-sea sampling system a lead-acid battery may
be used as the power source 216.
[0016] Thus, the sensor chassis 202 may provide a generic platform that may be dynamically
configured to compressively sample a plurality of input signals without requiring
any prior knowledge about the input signal or the desired application. Accordingly,
the generic nature of the sensor chassis 202 may greatly reduce manufacturing time
and complexity. Additionally, the dynamic configuration capability may also enable
implementation of a variety of applications using the same sensor chassis 202, thereby
reducing deployment costs and efforts. Accordingly, the processing subsystem 214 may
analyze the input signal 106 and the corresponding set of parameters to dynamically
determine an appropriate CS protocol to achieve the desired sampling performance.
Subsequently, the digitizing system 208 may use the determined CS protocol to compressively
sample, record and reconstruct the input signal 106. To that end, the digitizing system
208 may include an ADC 220, a clock 222, at least one programmable filter 224 and
a recording device 226 for sampling and recording the input signal 106. Therefore,
in the present embodiment, the sensor chassis 202 may be equipped to implement a variety
of applications without requiring any additional processing devices such as the computing
device 112 of FIG. 1.
[0017] In certain embodiments, the processing subsystem 214 may precondition the input signal
106 to accurately capture salient information corresponding to the input signal 106.
By way of example, the salient information may include one or more characteristics
corresponding to the input signal 106 such as an input signal structure, an input
signal bandwidth, an input signal peak power, and so on. The processing subsystem
214 may use the salient information to introduce sensing diversity to provide a distinct
signature or fingerprint to the input signal 106. Moreover, the processing subsystem
214 may analyze the corresponding set of parameters to determine an environmental
datum such as ambient noise and sensor chassis characteristics. Particularly, the
processing subsystem 214 may evaluate sensor chassis characteristics such as a sampling
rate of the ADC 220 and/or a desired sampling performance criterion to determine a
CS protocol for sampling the input signal 106 efficiently. In one embodiment, the
processing subsystem 214 may query the data repository 122 coupled to the sensor chassis
202 to determine an appropriate CS protocol for compressively sampling the input signal
106. To that end, the data repository 122 may include a plurality of CS protocols
devised for different input signals using conventional techniques, such as a distilled
sensing technique for astronomical imaging, a non convex compressed sensing for non-Gaussian
noise, and so on. Therefore, in accordance with aspects of the present technique,
the processing subsystem 214 may query the data repository 122 to determine the CS
protocol based on a previously stored correlation, if any, corresponding to the input
signal 106 and a CS protocol previously used to compressively sample the input signal
106. In one embodiment, the processing subsystem 214 may select the CS protocol corresponding
to the stored correlation to compressively sample the input signal 106. In certain
other embodiments, the processing subsystem 214 may further customize the selected
CS protocol in accordance with application or user requirements to achieve the desired
sampling performance.
[0018] Further, the processing subsystem 214 may communicate one or more instructions corresponding
to the determined CS protocol to the sampling control unit 210. Subsequently, the
sampling control unit 210 may adjust one or more settings corresponding to the programmable
filter 224 based on the determined CS protocol to achieve the desired sampling performance.
The one or more settings, for example, may correspond to selection of a desired bandwidth
to filter out noise, a desired sampling rate, a duty cycle of the input signal 106,
a desired sampling accuracy, a number of bits per sample, and so on.
[0019] The configuration of the programmable filter 224 may enable the sensor chassis 202
to compressively sample the input signal 106 according to the determined CS protocol.
Accordingly, the sensor chassis 202 may employ the ADC 220 and the clock 222 for converting
the analog input signal 106 to a sequence of quantized, periodic discrete-time samples.
Subsequently, the recording device 226 may record the sampled input signal 106, which
may be then be reconstructed by the processing subsystem 214.
[0020] Turning to FIG. 3, a flowchart 300 depicting an exemplary method for configuring
a sensor chassis, such as the sensor chassis 102 of FIG. 1 or the sensor chassis 202
of FIG. 2 is illustrated. The method may be described in a general context of computer
executable instructions that may be located in either or both of local and remote
computer storage media, such as memory storage devices. Further, in FIG. 3, the method
is illustrated as a collection of blocks in a logical flow graph, which represents
a sequence of operations that may be implemented in hardware, software, or combinations
thereof. The various operations are depicted in the blocks to illustrate the functions
that are performed generally during remotely receiving a set of parameters, determination
of a CS protocol, and compressive sampling phases. In the context of software, the
blocks represent computer instructions that, when executed by one or more processors,
perform the recited operations. The order in which the method is described is not
intended to be construed as a limitation, and any number of the described blocks may
be combined in any order to implement the method disclosed herein, or an equivalent
alternative method. Additionally, individual blocks may be deleted from the method
without departing from the spirit and scope of the subject matter described herein.
[0021] Determination of a CS protocol generally entails use of salient information such
as a set of parameters corresponding to an input signal. As used herein, the term
"set of parameters" may refer to a collection of one or more parameters corresponding
to the input signal, such as the input signal 106 of FIG. 1. In accordance with aspects
of the present technique, the set of parameters may include an environmental datum
associated with the input signal, a characteristic of the input signal, a parameter
corresponding to the sensor chassis, and a criterion specifying a desired sampling
performance. The method begins at step 302 with the sensor chassis remotely receiving
the set of parameters for compressively sampling the input signal. In one embodiment,
the sensor chassis may remotely receive the set of parameters from a user interface,
a data repository, a set of sensors, a digital communication link, or combinations
thereof. To that end, the user interface, the data repository, the set of sensors
and/or the digital communication link may be communicatively coupled to the sensor
chassis. By way of example, an operator may input the environmental datum, the input
signal characteristic, the sensor chassis parameter or the desired sampling performance
criterion through a user interface. Alternatively, the sensor chassis may receive
some or all of the parameters from the set of sensors over a communication network
such as the communication network 114 of FIG. 1.
[0022] Subsequently, at step 304, the sensor chassis may dynamically determine a CS protocol
for compressively sampling the input signal based on the remotely received set of
parameters for achieving a desired sampling performance. As previously noted, a processing
subsystem, such as the processing subsystem 214 of FIG. 2, may be employed to dynamically
determine a CS protocol by evaluating the received set of parameters. By way of example,
the processing subsystem 214 may analyze the received environmental datum to evaluate
the effect of ambient environment on the desired sampling performance. As previously
noted, the processing subsystem 214 may evaluate specified values corresponding to
the environmental datum such as an ambient noise bandwidth and/or an ambient noise
duty cycle while determining an appropriate CS protocol for compressively sampling
the first input signal 106. Similarly, the processing subsystem 214 may also consider
the sensor chassis parameter that specifies at least one of a type of ADC to be used,
a sampling rate, and a number of bits per sample to determine the CS protocol. By
way of example, in one implementation, the sensor chassis may include a 24-bit ADC,
such as the ADC 220 of FIG. 2, whereas the desired sampling performance may mandate
a precision of only 12 bits. Accordingly, the determined CS protocol may vary one
or more values corresponding to an appropriate programmable filter in the sensor chassis
to use only the first 12 bits of the 24 bits corresponding to the ADC.
[0023] In accordance with aspects of the present technique, the processing subsystem may
further customize the determined CS protocol to achieve the desired sampling performance.
As previously noted, the desired sampling performance may correspond to a maximum
acceptable difference between the input signal and a signal reconstructed according
to the determined CS protocol. By way of example, in an image compression application,
the processing subsystem may determine the CS protocol that not only considers image
structure and intra-image correlations, but also adheres to specified error limits
during image reconstruction.
[0024] Further, in accordance with aspects of the present technique, the processing subsystem
may determine the CS protocol to efficiently exploit the structure and other input
signal characteristics such as the input signal power spectral density, the input
signal average power, and so on. An exemplary implementation of how the processing
subsystem may determine the appropriate CS protocol for compressively sampling the
input signal will be discussed in greater detail with reference to FIG. 4.
[0025] FIG. 4 illustrates a graphical representation 400 of a plurality of input signal
characteristics corresponding to an input signal, such as the input signal 106 of
FIG. 1. Graph 402 depicts a power spectral density trace 404 in the absence of any
input signal. Accordingly, the sensor chassis assumes the depicted power spectrum
to be noise, such as, ambient environmental noise or receiver system noise. Further,
graph 406 illustrates a power spectral density corresponding to the input signal.
The power spectral density plot may provide one or more signal characteristics that
may be exploited while determining the CS protocol for sampling the input signal.
For example, the graph 406 indicates absence of any input signal energy above a frequency
denoted by reference numeral 408. A receiver front end may be programmed accordingly
to provide for a sharp cut-off above this frequency. Similarly, the graph 406 also
indicates absence of any appreciable input signal energy below a frequency denoted
by reference numeral 410. Additionally, graph 406 indicates absence of any appreciable
input signal energy between frequencies identified by reference numeral 412 and reference
numeral 414. The sensor chassis may use these signal characteristics to determine
a CS protocol that may enable configuration of appropriate settings corresponding
to one or more band pass filters, such as the programmable filter 224 of FIG. 2.
[0026] In a similar manner, graph 416 is a representation of a total power received at a
front end of a receiver, such as the receiver 204, coupled to the sensor chassis.
The total power at an instant of time may be defined as a sum of the power spectral
density over all frequencies at that instant. The graph 416 indicates that an input
signal 418 is only present intermittently over the illustrated period of time. Therefore,
while determining the CS protocol, a threshold 420 on the total power may be specified
such that compressive sampling may be enabled only when the total power equals or
exceeds the threshold 420. Moreover, the depicted input signal characteristics may
serve as identifiers of a signal class. Particularly, the input signal characteristics
may identify the signal class corresponding to the input signal. Accordingly, in one
embodiment, the sensor chassis may query a signal library stored in a data repository
coupled to the sensor chassis based on the identified input signal class to determine
an appropriate CS protocol for sampling the input signal. As previously noted, the
data repository such as the data repository 122 of FIG. 2 may include previously stored
correlations between input signal classes and CS protocols previously used to compressively
sample the corresponding input signals. Such an implementation may greatly reduce
processing time and effort required for determining appropriate CS protocols for compressively
sampling a plurality of input signals.
[0027] With returning reference to FIG. 3, at step 306, the input signal may be compressively
sampled by employing the CS protocol dynamically determined at step 304 of FIG. 3.
Further, at step 308, the sensor chassis may optionally monitor a sampling performance
of the sensor chassis to verify if the CS protocol yields reconstructed signals in
accordance with the desired sampling performance. In addition, the sensor chassis
may provide a visual an/or an audio alert through an output device, such as the output
device 218 of FIG. 2 upon determining that the desired sampling performance is not
achieved. Alternatively, based on desired application requirements, the sensor chassis
may provide an alert upon determining that the desired sampling performance is achieved.
[0028] The exemplary method, therefore, describes a technique for dynamically configuring
the sensor chassis to compressively sample input signals even where prior information
corresponding to the input signals or a desired application is not available. The
present technique, thus, allows for fabrication of a generic sensor chassis that may
be dynamically configured to implement changing application requirements, thereby
reducing the time and complexity involved in setting up and operating CS systems.
In accordance with further aspects of the present technique, an alternative embodiment
of the exemplary method for compressively sampling the input signal by using a portable
sampling control unit is presented and will be discussed in greater detail with reference
to FIG. 5.
[0029] FIG. 5 illustrates a flowchart 500 depicting an alternative method for compressively
sampling an input signal using a portable sampling control unit, such as the sampling
control unit 128 of FIG. 1. The flowchart 500 corresponds to the description of FIG.
1, where the sampling control unit 128 is available as an independent unit that may
be programmed and subsequently coupled to the sensor chassis to facilitate compressive
sampling of the input signal. It may be noted that one or more steps of the flowchart
500 may correspond to one or more steps of the flowchart 300 described with reference
to FIG. 3. Therefore, such steps may not be discussed in detail in the ensuing description
of the flowchart 500.
[0030] As previously described with reference to the step 302 of FIG. 3, at step 502, the
sensor chassis may remotely receive a set of parameters for compressively sampling
the input signal. Further, at step 504, the sensor chassis may dynamically determine
a CS protocol for compressively sampling the input signal based on the remotely received
parameters. Particularly, the sensor chassis may evaluate the set of parameters to
dynamically select or customize the CS protocol such that a desired sampling performance
is achieved, as described with reference to step 304 of FIG. 3.
[0031] Subsequently, at step 506, the sampling control unit may be programmed to store one
or more instructions corresponding to the determined CS protocol. In accordance with
aspects of the present technique, the sampling control unit may be an independent
unit such as the sampling control unit 128 described with reference to FIG. 1. Further,
as previously noted, the sampling control unit may include at least one of a memory
device, a programmable device, a control device, and a digital control link. By way
of example, the sampling control unit may include an FPGA, an optical disk, a tape,
a compact disk, and so on. Once the one or more instructions are stored, the sampling
control unit may then be communicatively coupled to the sensor chassis for appropriately
varying values of one or more settings corresponding to a plurality of programmable
filters, as indicated by step 508. Particularly, the sampling control unit may vary
the one or more settings based on the determined CS protocol to achieve the desired
sampling performance.
[0032] Thus, in accordance with aspects of the present technique, a generic sensor chassis
deployed in a field may remotely receive or detect a set of parameters representative
of the input signal to be sampled. An appropriate CS protocol may be determined for
sampling the input signal based on the remotely received set of parameters that may
include application and user requirements. Instructions corresponding to the determined
CS protocol may be stored on a sampling control unit. Subsequently, the sampling control
unit having the stored instructions may be installed in the generic sensor chassis.
The sampling control unit may, thus, facilitate the generic sensor chassis to compressively
sample the input signal according to the determined CS protocol to achieve the desired
sampling performance as indicated by step 510. Further, as previously described with
reference to step 308 of FIG. 3, at step 512, the sampling control unit may optionally
provide instructions to the sensor chassis for monitoring a sampling performance of
the sensor chassis. Particularly, the sensor chassis may verify if the determined
CS protocol yields reconstructed signals in accordance with the desired sampling performance
based on the instructions received from the sampling control unit. Additionally, the
sampling control unit may direct the sensor chassis to provide an alert through an
output device coupled to the sensor chassis upon determining that the desired sampling
performance is not achieved. Thus, the ability of the sampling control unit to be
programmed independently and later disposed in a generic sensor chassis to implement
desired functions imparts a great amount of portability to a sensor chassis implementation.
[0033] The exemplary system and method described hereinabove, thus, enable dynamic configuration
of multiple CS protocols to sample a plurality of input signals based on the structure
of the input signal, ambient conditions and application and user requirements. The
dynamic configuration capability allows quick adaptation to changing application requirements
without requiring additional or new hardware, thereby conserving space and battery
power. Moreover, the dynamic configuration also allows correction or mitigation of
programming errors that may be detected after deployment of the sensor chassis. More
particularly, the exemplary method enables fabrication of a generic sensor chassis
that may be deployed anywhere and configured 'on the fly' to sample a plurality of
input signals for a variety of different applications.
[0034] While only certain features of the present invention have been illustrated and described
herein, many modifications and changes will occur to those skilled in the art. It
is, therefore, to be understood that the appended claims are intended to cover all
such modifications and changes as fall within the true spirit of the invention.
[0035] Various aspects and embodiments of the present invention are defined by the following
numbered clauses:
- 1. A method for configuring a sensor chassis, comprising:
remotely receiving a set of parameters for compressively sampling an input signal;
dynamically determining a compressive sampling protocol for compressively sampling
the input signal based on the remotely received set of parameters for achieving a
desired sampling performance; and
compressively sampling the input signal according to the determined compressive sampling
protocol.
- 2. The method of clause 1, wherein the received set of parameters comprises an environmental
datum associated with the input signal, a characteristic of the input signal, a parameter
corresponding to the sensor chassis, and a criterion specifying the desired sampling
performance.
- 3. The method of any preceding clause, wherein the environmental datum associated
with the input signal specifies at least one of an ambient noise bandwidth, an ambient
noise duty cycle, an ambient noise power spectral density, an ambient noise average
power, and an ambient noise peak power.
- 4. The method of any preceding clause, wherein the characteristic of the input signal
specifies at least one of an input signal bandwidth, an input signal duty cycle, an
input signal power spectral density, an input signal average power, and an input signal
peak power.
- 5. The method of any preceding clause, wherein the parameter corresponding to the
sensor chassis specifies at least one of a type of an analog-to-digital converter
to be used, a sampling rate, and a number of bits per sample.
- 6. The method of any preceding clause, wherein the criterion specifying the desired
sampling performance is a maximum acceptable difference between the input signal and
a signal reconstructed according to the determined compressive sampling protocol.
- 7. The method of any preceding clause, wherein remotely receiving the set of parameters
comprises receiving the set of parameters from at least one of a user interface, a
data repository, a set of sensors, and a network communication link, wherein the user
interface, the data repository, the set of sensors and the network communication link
are communicatively coupled to the sensor chassis.
- 8. The method of any preceding clause, wherein compressively sampling the input signal
according to the determined compressive sampling protocol comprises:
storing one or more instructions corresponding to the determined compressive sampling
protocol on a sampling control unit; and
communicatively coupling the sampling control unit to the sensor chassis.
- 9. The method of any preceding clause, wherein the sampling control unit comprises
at least one of a memory device, a programmable device, and a control device.
- 10. The method of any preceding clause, further comprising:
monitoring a sampling performance of the sensor chassis; and
alerting if the desired sampling performance is not achieved.
- 11. The method of any preceding clause, further comprising customizing the determined
compressive sampling protocol upon determining that the desired sampling performance
is not achieved.
- 12. A sensor chassis, comprising:
a receiver that receives an input signal;
a processing subsystem that:
remotely receives a set of parameters for compressively sampling the input signal;
dynamically determines a compressive sampling protocol for compressively sampling
the input signal based on the remotely received set of parameters for achieving a
desired sampling performance; and
one or more programmable filters, each programmable filter having at least one setting,
wherein a value corresponding to each of the at least one setting is adjusted according
to the determined compressive sampling protocol,
wherein the sensor chassis compressively samples the input signal according to the
determined compressive sampling protocol.
- 13. The sensor chassis of any preceding clause, wherein the processing subsystem remotely
receives the set of parameters from at least one of a user interface, a data repository,
a set of sensors, and a network communication link, wherein the user interface, the
data repository, the set of sensors and the network communication link are communicatively
coupled to the sensor chassis.
- 14. The sensor chassis of any preceding clause, further comprising a sampling control
unit, wherein the sampling control unit receives one or more instructions corresponding
to the determined compressive sampling protocol from the processing subsystem.
- 15. The sensor chassis of any preceding clause, wherein the sampling control unit
comprises at least one of a memory device, a programmable device, and a control device.
- 16. The sensor chassis of any preceding clause, wherein the processing subsystem further:
monitors a sampling performance of the sensor chassis; and
generates an alert based on the monitored sampling performance.
- 17. The sensor chassis of any preceding clause, further comprising a data repository
for storing a plurality of compressive sampling protocols.
- 18. The sensor chassis of any preceding clause, wherein the data repository further
stores a correlation between each of the plurality of compressive sampling protocols
and at least one input signal.
- 19. The sensor chassis of any preceding clause, wherein the processing subsytem dynamically
determines the compressive sampling protocol for compressively sampling the input
signal based on a stored correlation corresponding to the input signal.
- 20. The sensor chassis of any preceding clause, wherein the processing subsytem customizes
the determined compressive sampling protocol for compressively sampling the input
signal based on the remotely received parameters.
1. A method (300) for configuring a sensor chassis (102), comprising:
remotely receiving (302) a set of parameters for compressively sampling an input signal;
dynamically determining (304) a compressive sampling protocol for compressively sampling
the input signal based on the remotely received set of parameters for achieving a
desired sampling performance; and
compressively sampling (306) the input signal according to the determined compressive
sampling protocol.
2. The method (300) of claim 1, wherein the received set of parameters comprises an environmental
datum associated with the input signal, a characteristic of the input signal, a parameter
corresponding to the sensor chassis, and a criterion specifying the desired sampling
performance.
3. The method (300) of any preceding claim, wherein compressively sampling the input
signal according to the determined compressive sampling protocol comprises:
storing one or more instructions corresponding to the determined compressive sampling
protocol on a sampling control unit; and
communicatively coupling the sampling control unit to the sensor chassis.
4. The method (300) of any preceding claim, further comprising:
monitoring (308) a sampling performance of the sensor chassis; and
alerting if the desired sampling performance is not achieved.
5. The method (300) of claim 4, further comprising customizing the determined compressive
sampling protocol upon determining that the desired sampling performance is not achieved.
6. A sensor chassis (102), comprising:
a receiver (116) that receives an input signal;
a processing subsystem (214) that:
remotely receives a set of parameters for compressively sampling the input signal;
dynamically determines a compressive sampling protocol for compressively sampling
the input signal based on the remotely received set of parameters for achieving a
desired sampling performance; and
one or more programmable filters, each programmable filter having at least one setting,
wherein a value corresponding to each of the at least one setting is adjusted according
to the determined compressive sampling protocol,
wherein the sensor chassis (102) compressively samples the input signal according
to the determined compressive sampling protocol.
7. The sensor chassis (102) of claim 6, further comprising a sampling control unit (128,
210), wherein the sampling control unit (128, 210) comprises at least one of a memory
device, a programmable device, and a control device, and wherein the sampling control
unit (128, 210) receives one or more instructions corresponding to the determined
compressive sampling protocol from the processing subsystem.
8. The sensor chassis (102) of claim 6 or claim 7, wherein the processing subsystem (214)
further:
monitors a sampling performance of the sensor chassis (102); and
generates an alert based on the monitored sampling performance.
9. The sensor chassis (102) of any of claims 6 to 8, further comprising a data repository
(122) for storing a plurality of compressive sampling protocols and a correlation
between each of the plurality of compressive sampling protocols and at least one input
signal.
10. The sensor chassis (102) of any of claims 6 to 9, wherein the processing subsytem
(214) dynamically determines the compressive sampling protocol for compressively sampling
the input signal based on a stored correlation corresponding to the input signal.